[evlatests] P-Band on Antennas 23 and 17

[Jim Jackson]

P-Band is now available for testing on Antenna 17 and 23.  The problem in 
23 was finally tracked down to a shorted cable at the Apex (which also let 
the smoke out of an F14 module - sorry Wayne).  Antenna 17 worked first try 
yesterday when we installed the T301.  We are seeing reasonable total 
power, ALC and switched power readings at the T5 and good spectrum displays 
from Mike's real time spectrum displays.

Right now the Psystart script sets the T304 attenuators to -1, -1.  This 
results in excessive levels to the digitizers (RMS around 70).  Someone 
needs to calibrate the levels.  Our experimentation produced the best 
results (at the T5) with T304 RF attenuator settings in the range of 8-12dB 
and CH1 attenuator settings in the range of 20-24dB.

Jim